1. Field of the Invention
The present invention relates to a recording tape cartridge. More particularly, the present invention pertains to a recording tape cartridge in which a single reel, with a recording tape such as a magnetic tape usable as a recording and reproducing medium for a computer or the like being wound thereon, is accommodated in a case.
2. Description of the Related Art
There has heretofore been known a recording tape cartridge in which a recording tape such as a magnetic tape usable as a recording and reproducing medium for a computer or the like is wound on a reel, and the reel is rotatably accommodated in a case formed from a synthetic resin. The recording tape cartridge is arranged such that when in use (when loaded into a drive device), the reel is rotatable in the case, while when in non-use (when not loaded into a drive device), the reel is locked so as to be non-rotatable in the case.
More specifically, the recording tape cartridge includes a brake section for preventing the reel from being rotated within the case when the cartridge is in non-use. The brake section may be constructed such that a brake member, which for example is non-rotatable with respect to the case, can be engaged with the reel.
As shown in FIG. 18, for example, a brake member 200 is configured in the form of a disk which is disposed in such a manner as to be vertically movable within a bottomed, generally cylindrical shape reel hub 204 of a reel 202. A pair of engagement projections 206 which define an approximate U shape as seen in a plan view are provided upright on the upper surface of the brake member 200. A pair of rotation regulating ribs 210 depending from the inner surface of an upper case section 208 are inserted inside the engagement projections 206, thereby making the brake member 200 non-rotatable with respect to the case 212.
Further, the brake member 200 is normally biased toward a bottom wall 216 of the reel hub 204 with the aid of a biasing member such as compression coil spring 214, so that an annular brake gear 218 formed in the lower surface of the brake member 200 is meshed with an annular engagement gear 220 formed in the upper surface of the bottom wall 216 of the reel hub 204. In this manner, the reel 202 is prevented from inadvertent rotation.
Still further, a generally cylindrical operation projection 222, which is projectingly provided at an axial center portion of the lower surface of the brake member 200, is inserted in a through hole 216A formed in an axial center portion of the bottom wall 216 of the reel hub 204, and exposed through a gear opening 226 formed substantially at a center portion of a lower case half 224. In an attempt to make the reel 202 rotatable, the operation projection 222 (brake member 200) is pushed upward, and as a result the brake gear 218 is disposed out of engagement with the engagement gear 220 (refer to U.S. Pat. No. 6,452,747, for example).
However, with the above-described arrangement, when the recording tape cartridge is in a non-use state, the reel 202 is movable upward (movable axially of the reel 202) against a biasing force of the biasing member such as compression coil spring 214. It is likely that in case the bottom wall 216 of the reel hub 204 is moved upward because of the recording tape cartridge being impacted due to dropping or the like, the brake member 200 becomes tilted and jammed at the edge of the through hole 216A while being in a tilted orientation (being on the point of falling) as shown in the drawing.
If the recording tape cartridge is loaded into a drive device under such a condition, there tends to arise a problem that not only the recording/reproducing operation cannot be performed but also the recording tape cartridge is damaged or the drive device malfunctions. Another problem is that an adverse affect arises since the reel becomes rotatable when in non-use, the recording tape tends to get wrinkled or torn off.